Generation of automatic stippling illustrations from photographs for documenting archaeological pieces

[EN] Hand-made stippling has been used frequently in the process of drawing illustrations for documenting archaeological pieces. This is due to the fact that this technique represents in an efficient way shapes, tones, and textures, by means of distributing dots on the paper. The process of stippling has needed traditionally the ability of an artist, who usually produces the illustration from photographs. In this paper, a program that generates stippling illustrations of high quality is presented. The developed interface makes possible that any user can generate illustrations without the need of artistic abilities. The program is able to work in realtime, allowing the user interacts with the program. We have developed several artistic techniques in high level tasks that allow to improve the final results.[ES] El punteado manual se ha utilizado frecuentemente en el proceso de ilustración para documentar piezas arqueológicas. Esto se debe a que esta técnica es capaz de representar de forma eficiente formas, tonalidades y texturas mediante la distribución de puntos en un papel. Estas ilustraciones requieren las habilidades de un artista, el cual utiliza fotografías para realizarlas. En este artículo se presenta un software que genera ilustraciones punteadas de alta calidad de forma automática. La interfaz desarrollada hace posible que cualquier usuario pueda generar ilustraciones sin la necesidad de habilidades artísticas. El programa trabaja en tiempo real permitiendo al usuario interactuar con el mismo. Hemos implementado varias técnicas empleadas por artistas como simples tareas de alto nivel que mejoran los resultados finales.Authors thank the collaboration of the illustrator Elena Piñar. Thanks to the Ministerio de Educación y Ciencia of Spain for the projects TIN2007-67474-C03-02 and TIN2007-67474-C03-01, which have partially funded this work.Arroyo, G.; Martín, D.; Luzón, MV. (2011). Generation of automatic stippling illustrations from photographs for documenting archaeological pieces. Virtual Archaeology Review. 2(3):59-64. https://doi.org/10.4995/var.2011.4606OJS596423SECORD, A. (2002): "Weighted voronoi stippling". In Proc. of NPAR, ACM Press, pp. 37-43. http://dx.doi.org/10.1145/508530.508537DEUSSEN O. et al. (2000): "Floating points: A method for computing stipple drawings". Computer Graphics Forum 19, pp. 40-51. http://dx.doi.org/10.1111/1467-8659.00396HILLER, S. et al. (2003): "Beyond Stippling - Methods for Distributing Objects on the Plane". Computer Graphics Forum 22, 3, September, pp. 515-522. http://dx.doi.org/10.1111/1467-8659.00699DALAL, K. et al. (2006): "A Spectral Approach to NPR Packing". In Proc. of NPAR, ACM, New York, pp. 71-78. http://dx.doi.org/10.1145/1124728.1124741BARLA, P. et al. (2006): "Interactive hatching and stippling by example". INRIA.SECORD A. et al. (2002): "Fast primitive distribution for illustration". In Thirteenth Eurographics Workshop on Rendering, pp. 215-226.SCHLECHTWEG S. et al. (2005): "Renderbots: Multi agent systems for direct image generation". Computer Graphics Forum 24, 283-290. http://dx.doi.org/10.1111/j.1467-8659.2005.00838.xMOULD D. (2007): "Stipple placement using distance in a weighted graph". In Proc. of Computational Aesthetics in Graphics, no. 3. p. unknown.KIM, S. et al. (2009): "Stippling By Example". In Proc. of NPAR, ACM, New York, pp. 41-50. http://dx.doi.org/10.1145/1572614.1572622ISENBERG, T. et al. (2005): "Breaking the Pixel Barrier". In Proc. of Cae, Eurographics Association, Aire-la-Ville, Switzerland, pp. 41-48.MACIEJEWSKI R. et al. (2008): "Measuring Stipple Aesthetics in Hand-Drawn and Computer-Generated Images", IEEE Computer Graphics and Applications, pp. 62-74. http://dx.doi.org/10.1109/MCG.2008.3

What’s On the Surface Does Matter: The Conservation of Applied Surface Decoration of Historic Stained Glass Windows

A stained glass window is both an architectural building element and an individual work of art. Like architecture, a stained glass window is composed of a variety of materials, mainly glass, lead, and surface decoration, each of which has its own conservation issues. Surface decoration, which includes vitreous glass paint, silver stain, and enamels, is the component of a stained glass window that is sometimes underappreciated. While it may not pose a major threat to the physical stability of the window or the safety of the window’s environment, it is the decoration that defines the windows as works of art, with imagery that holds the window’s history, including a direct view into the traditions, ideals, and beliefs of the people of their time. The conservation of the surface decoration of stained glass windows has never been fully analyzed, and both glazing and conservation professionals are constantly seeking information regarding the history of the materials and techniques used in order to create or restore a stained glass window. With conservation, the methods and techniques used to maintain and conserve the decoration will vary depending on a number of circumstances, including the location of the window, the history and traditions of the people involved, and the tools available to the conservators. As with all conservation fields, there are also ethical considerations to address in order to be sure that the authenticity of each work is maintained. For this history, it is also important to note the past restoration techniques used on these types of decoration, as well as what is being used today. This includes successes and failures, both of which bring essential information to the conservator. Each window brings with it an entirely new history and set of decoration conservation problems so there are no universal solutions for this field. Stained glass is a fascinating field because it combines the worlds of art and architecture with a single object and the surface decoration plays an important role in this. By analyzing the history and techniques of these three surface decorations, it is possible to not only preserve an underappreciated element inherent to these historic stained glass windows, but also the overall aesthetic of true works of art that serve to enhance the buildings in which they reside